Currently, the exterior walls have batt insulation. It has the paper face on one side. A few months ago, I removed a window due to watered down drywall caused by the window. At the time, I didn't check to see if the insulation was the kind with a vapor barrier. (there is no plastic, that I know for sure) However, I dont know if the insulation installed was the kind with a vapor barrier.
Now, we have decided to do cellulose at some point. We are currently doing a remodel of 2 rooms so I need to decide if I should remove the drywall and the insulation and then get cellulose blown in. Or if I should leave the drywall and insulation as is and when we get new siding at some point, have cellulose blown in with the batt insulation.
Are there any advantages/disadvantages of leaving the batt insulation alone? Do I need to worry about there possibly not being a vapor barrier?
Best Answer
Dense-packed (and only dense-packed, not loose-blown) cellulose is better in walls than fiberglass batts, for a couple of reasons.
That said, unless your fiberglass batts are wet or moldy, it's probably not cost-effective to remove them, especially if leaving them in means you can avoid tearing off perfectly good drywall. The kraft paper facer on most batts is not a vapor barrier, it's a vapor retarder, which is fine. Very few batts have foil facers, which are vapor barriers. Even if your batts have vapor barrier facers, I see that you live in Wisconsin, which is a place where you can get away with having a vapor barrier without it being too bad (most of the time you don't want a vapor barrier in your walls). I'd leave the batts in.